1. Field of the Invention
The present invention generally relates to adding a hop flavor to beverages. More particularly, it relates to novel methods of preparing fully kettle hop flavored beverages and compositions for use in such methods.
2. Background of the Art
Hops, in the form of either the ground dried plant or pellets, are used in brewing to give the beverages, such as beer or ale, their characteristic bitter flavor and pleasant aroma. The hops usually are added to the boiling wort in the brewing kettle. Alternatively, if primarily a bitter flavor is desired, a hop extract can be added to the brewing kettle or an isomerized hop extract, if it is highly purified, may be added post kettle, i.e., after the wort has been boiled or after fermentation.
The primary hop constituents which are utilized in the brewing process are the alpha acids, the beta acids, the uncharacterized resins and the hop oils. The alpha acids are known as humulones and the beta acids are known as lupulones. The alpha acids are the precursors of the bitter substances in beer. The beta acids or lupulones have low solubility in wort and beer and they are believed to play a relatively minor role in the brewing process.
During brewing, chemical changes are made in the alpha acids or humulones resulting in the formation of compounds known as iso-alpha acids, i.e., isohumulone, isocohumulone and isoadhumulone. The alpha acids are extracted from the hops by the boiling wort and isomerized to the iso-alpha acids during the kettle boiling stage.
It is known that iso-α-acids derived from hops (or an unreduced hop extract which contains iso-α-acids) can cause light instability in malt beverages. The exposure of such a beverage to light can result in the beverage becoming “light struck” and having a skunky odor. As a result, such beverages cannot be packaged in clear or green glass bottles without a risk of developing the “light struck” character. Light stable beers that can be packaged in clear or green glass bottles are made using reduced hop extracts.
Hop extracts have been used in brewing beer for a number of years. The reasons are several-fold. When whole hops are added to the kettle, the yield of iso-alpha acids is poor, e.g., 10–25% based on the alpha acids present in the hops. However, the conversion of alpha acids in a hop extract to iso-alpha acids can be very high, e.g. 80%. Furthermore, the utilization of the pure iso-alpha acids in a preisomerized extract which is added post kettle is known to be extremely high, e.g. 70–90%.
The predominant production of hop extracts consists of extracting the essential bittering acids from the cellulosic material of the hop blossom by the use of either organic solvents or carbon dioxide. The hop extracts thus obtained can be added to the brewing kettle or chemically processed to isomerize and reduce the alpha acids. The hops from which the alpha acids have been removed are generally referred to as “spent hops” (but hereinafter referred to as “hop solids”) and they are discarded or sold as animal feed.
We have discovered that one disadvantage of adding hop extracts to the wort in the kettle is that the beer produced lacks the full flavor and aroma produced when whole hops are added to the wort in the kettle. As a result, fermented beverages, such as beer, which have been prepared using hop extracts, although they may have the bitterness of beverages prepared from whole hops, do not have the same full hop flavor as fermented beverages made with whole hops. However, the use of whole hops to obtain the full hop flavor results in a very bitter tasting beverages which may not be desired.
There are other disadvantages to using hop extracts. For example, the use of a CO2 or hexane hop extract does not produce a light stable or fully kettle hopped beverage. Also, use of a processed CO2 hop extract (to make “hydrohop”) does not produce a fully kettle hopped beverage. It would be advantageous to have a method of preparing less bitter, fermented beverages having the same “full hop flavor” as fermented beverages prepared with the use of whole hops.
It has been surprisingly discovered that the use of hop solids or an extract of hop solids produces a light stable, fully kettle hopped beverage. Several of the inventors have disclosed (in a separate co-pending patent application) a method of preparing a full hop flavored beverage using hop solids. Hop solids have historically been a useless by-product of the hop extraction process. It has now been surprisingly discovered that an extract of the hop solids can be used to produce a beer judged to have a superior hop flavor when compared to a beverage made from hop extracts or even to a beverage made from hop solids themselves.
It is important to note that the “full” or “kettle” hop flavor refers to the flavor derived from whole hops or hop pellets after fermentation, not the original aroma of whole hops, hop pellets, CO2 hop extract, or even hop character fraction.